Falls among the elderly are at epidemic proportions worldwide. Approximately one out of every three seniors fall in any given year, and these falls are the most common cause of injury and hospital admissions among this group. In 2003, the last year data available from the U.S. Centers for Disease Control and Prevention (CDC), 1.8 million U.S. elders were treated in emergency departments for nonfatal injuries related to falls and 13,700 died of fall-related injuries. By 2020, the CDC estimates that the annual cost of falls among the elderly will be $43.8B. Furthermore, it has been shown that the longer seniors have to wait for help to arrive after they have fallen, the higher the chances are that they will die, have to be admitted to the hospital, or end up in a nursing home. Therefore, it is critical to get help to people as quickly as possible if they fall.
Falls are not only an issue for the elderly living in their own homes. People in acute-care, rehabilitation and psychiatric hospitals, skilled nursing facilities, independent and assisted living facilities also are vulnerable to falls. These institutions are also susceptible to liability risks when their patients or residents fall.
The magnitude of the problem of falls among the elderly has been apparent for many years, and hence there have been many prior art attempts to create fall prevention or detection systems that address this concern.
The simplest and most common solution to the detection of falls among the elderly is not a true detection system, but rather simply employs a “panic button”. Systems of this type are often called Personal Emergency Response Systems (PERS), and are provided by companies such as Philips LifeLine, Framingham, Mass. If a person has fallen or otherwise needs help, they push a button on a transmitter that is worn around their neck or on their wrist. This transmitter sends a radio signal to a receiver/speaker-telephone, which is plugged into the telephone line. The reception of the radio signal causes the receiver/speaker-telephone to call a preprogrammed telephone number of a response center, where the phone is answered by an operator. The operator can then use the speaker-telephone to ask the victim if they need help. The obvious and significant limitations of this approach include: (i) the need for the elderly person to push the button, which may be difficult if the person is unconscious or has dementia so forgets the button; (ii) the elderly person must always have the button within reach (even at night); (iii) the button/transmitter must be within radio range of the receiver/speaker-phone; and (iv) many elderly people do not enjoy wearing the button.
Other conventional systems also have significant drawbacks. For example, another prior art system employs a load-sensor that is integrated into a bed or chair, or can be implemented by placing a pad, sheet-liner or other similar device on the bed, chair or floor next to the bed to detect if a patient has moved off the bed or chair. Products representative of this approach are sold under the tradename NoFalls® by Hill-Rom (Batesville, Ind.), alarms and pads from AliMed (Dedham, Mass.), and the Tabs System® from Stanley Senior Technologies (Lincoln, Nebr.).
U.S. patent application publication no. 2008/272918A1 describes how sensors of this type can be configured as a system. However, all of these systems are limiting in that the potential fall victim must normally be in the bed or chair and their exit from the bed must represent an unusual circumstance. These solutions only work for patients who spend essentially all of their time in bed. Even for the sickest elderly patient who is still in their home, or patients who simply wish to get out of bed to use the bathroom, these solutions are impractical.
U.S. Pat. No. 5,490,046 describes another even more limiting “bed exit alarm” type system where a short string is connected between an alarm and the patient—when the patient leaves the bed, the string is pulled out of the device which in turn activates an alarm. U.S. Pat. Nos. 5,471,198, 6,204,767, 6,211,787 and 6,788,206 describe variations on this theme where a sensor measures the distance a patient is from the head of the bed or the back of the chair and alarms if that distance changes. Again, these prior art systems require the potential victim to be normally confined to a bed or chair.
Another prior art approach is to have a potential fall victim wear an accelerometer. This accelerometer is tuned such that if the person wearing the device falls down, the accelerometer detects the force of impact and sends a radio signal to a similar receiver/speaker-phone as described above. There are many variations on this theme in the art. An example of this type includes PCT Publication Number WO 2006/038941A2 which describes a fall-sensor accelerometer that is integrated into a mobile phone. A commercial product based on the accelerometer approach is offered by Tunstall (Yorkshire, UK). Systems of this type primarily attempt to overcome historically significant limitations such as false alarms generated when the patient sits or lays down abruptly. However, none of the prior art overcomes the fundamental flaw in the approach that the potential fall victim must wear the device on their person constantly—even at night. Other limitations include (i) the relatively high rate of false alarms generated from normal activities of daily living (ADL) or having the sensing accelerometer accidentally drop to the floor; (ii) the relatively high cost of such a device; (iii) like the PERS above, the sensing device must be within radio range of the receiver/speaker-phone; and, similar to the PERS, (iv) many elderly patients do not enjoy wearing the accelerometer.
Another prior art solution is the whole-house monitoring systems or “Smart Homes.” Prior art systems of this type have the potential to indirectly address the problem of fall detection by determining if the elder's normal ADL habits are compromised. These systems rely on sensors placed throughout the elder's home which communicate to a computer that infers ADL activities. For example, if a motion sensor in the bedroom normally senses movement at approximately 7:00 AM every morning, then one day if there has been no motion sensed by 8:00 AM, the system may infer that something is wrong and call for help. Systems such as described in U.S. Pat. Nos. 4,259,548, 6,445,298, 6,696,957, 6,825,761, 7,242,305 and 7,405,653. An example of prior art systems of this type is disclosed and described in U.S. patent application publication no. 2008/0186189A1 which employs an algorithmic approach to gathering data and inferring ADL levels from the data. However, none of these systems directly detects falls, but rather infer that a fall or other emergency has occurred because the dweller's normal patterns have changed. These systems are severely limited because (i) they only work with a single person living in the home; (ii) they require complex and expensive computer and sensor infrastructures to be installed throughout the entire home; and (iii) most significantly, they typically take many tens-of-minutes to hours before they determine that a pattern is truly changed and hence an alarm should be generated—these are many hours that a fall victim is potentially lying in pain on the floor.
Yet another prior art approach is to sense vibrations in the floor to determine if something large has unexpectedly hit the floor. Two published U.S. patent applications that describe this approach are 2006/0195050A1 and 2007/0112287A1. While this approach has the advantage of not requiring the user to wear anything, it appears to be of limited practicality. Practically deploying a system such as this is difficult because the system needs to be “tuned” to different flooring materials (cement, wood, carpeting, etc.) and building constructions (apartment vs. single home, first-floor vs. second-floor, etc.) Fundamentally, such an approach is limited because it will never be able to distinguish the vibrations generated from a 90 lb elderly women falling to the floor from those of a 90 lb dog jumping off the couch.
More direct monitoring approaches have also been tried. Indeed, a video monitoring system has also been suggested to detect falls, as set forth for example in U.S. Pat. Nos. 6,049,281 and 7,110,569, and in U.S. patent application publication no. 2003/0058111A1. While this approach again has the advantage of allowing remote detection of falls, it has a very significant limitation in that it requires video cameras to be constantly monitoring all the rooms of the elder's home. This creates obvious and significant privacy concerns.
Finally, there are also a variety of approaches which are based on conventional motion detectors used in security systems. While not a fall sensor, U.S. Pat. No. 5,023,593 describes a swimming pool alarm which senses motion in a thin zone just above the water. U.S. Pat. No. 6,462,663 teaches that complex lensing can be used with motion sensors to create many smaller zones, essentially creating a grid in a room, to be used for location and tracking. U.S. Pat. No. 5,905,436 describes a fall sensor which uses two conventional security system motion detectors which effectively divide a room into two horizontal sections, for example, a top half and a bottom half. If the system initially detects motion in both the top and bottom halves, then subsequently only in the bottom half, it concludes that there is a fall. This system has an advantage over the aforementioned solutions in that it does not require the person to wear a device or take any deliberate action (other than falling) to generate an alarm. However, there are several serious limitations with this approach which makes its use by an elderly patient impractical. First, solutions that use conventional motion detectors are extremely prone to false alarms generated by pets, children or even changes in heat. Second, the approach is flawed if the person falls and becomes unconscious, since the algorithm cannot distinguish an unconscious fall victim from no motion in the room. In this circumstance, no alarm sounds. Third, motion detectors are optimized for security use and hence are optimized for side-to-side (i.e. walking) movement. Consequently, the up-and-down movement of a fall is harder for systems of this type to detect which can lead to missed events. Finally, systems of this type require custom installation, mounting of motion detectors near the ceiling and “tuning” of the motion detectors' reception pattern for each room of the home, and hence are expensive and difficult to install.